The database of mutation Markers for anti-cancer drug Sensitivity (dbMCS) is a comprehensive literature-based database of mutation markers that indicate drug sensitivity or resistance. At present, the dbMCS contains 3136 unique entries recording mutation-disease-drug relationships with sensitivity and 1275 unique entries with resistance, involving in 185 cancer types or subtypes, and 463 kinds of anti-cancer drugs. Users can browse or search the relevant information by different key words conveniently. These data can be used to improve and evaluate the algorithm for identifying the mutation markers of anti-cancer drug sensitivity and predicting drug sensitivity.